The "costly signalling" hypothesis proposes that animal signals are kept honest by appropriate signal costs. We show that to the contrary, signal cost is unnecessary for honest signalling even when interests conflict. We ...

Both plants and animals respond to stress by using adaptations that help them evade, tolerate, or recover from stress. In a synthetic paper A. D. Bradshaw (1972) noted that basic biological differences between plants and ...

Mathematical models are valuable tools with which to predict and explain the epidemiology of nosocomial infection. As such, modeling will play a crucial role in the effort to control the growing threat posed in hospitals ...

Why do parasites harm their hosts? The general understanding is that if the transmission rate and virulence of a parasite are linked, then the parasite must harm its host in order to maximize its transmission. The exact ...

Much of the theoretical literature on costly signalling concentrates on the separating equilibria of continuous signalling games. At such equilibria, every signaller sends a distinct signal, and signal receivers are able ...

Background: Doherty and Zinkernagel, who discovered that antigen presentation is restricted by the major histocompatibility complex (MHC, called HLA in humans), hypothesized that individuals heterozygous at particular MHC ...

Recent experimental results show that even brief stimulation with antigen can cause antigenspecic CD8 T-cells to undergo sustained proliferation followed by differentiation into memory cells. These results show that the ...

It is unclear when, where and how novel pathogens such as human immunodeficiency virus (HIV), monkeypox and severe acute respiratory syndrome (SARS) will cross the barriers that separate their natural reservoirs from human ...

Mutualisms provide benefits to those who participate in them. As a mutualism evolves, how will these benefits come to be allocated among the participants? We approach this question using evolutionary game theory and explore ...

Background: Doherty and Zinkernagel, who discovered that antigen presentation is restricted by the major histocompatibility complex (MHC, called HLA in humans), hypothesized that individuals heterozygous at particular MHC ...

Recent studies have found high frequencies of bacteria with increased genomic rates of mutation in both clinical and laboratory populations. These observations may seem surprising in light of earlier experimental and ...

RNA silencing, found broadly throughout the eukaryotes, post-transcriptionally suppresses the expression of aberrant genes including those of many viruses and transposons. Similar to the specific immune system of vertebrates, ...

Hospital-acquired infections caused by antibiotic-resistant bacteria pose a grave and growing threat to public health. Antimicrobial cycling, in which two or more antibiotic classes are alternated on a time scale of months ...

Scientific publishing is rapidly shifting from a paper-based system to one of predominantly electronic distribution, in which universities purchase site licenses for online access to journal contents. Will these changes ...

Health officials faced a daunting task with the emergence of severe acute respiratory syndrome (SARS) last year: forecasting the trajectory of an emerging infectious disease and implementing effective control measures, ...

Cytosine methylation is an epigenetic mechanism in eukaryotes that is often associated with stable transcriptional silencing, such as in X-chromosome inactivation and genomic imprinting. Aberrant methylation patterns occur ...